Field device adapter for wireless data transfer

A system of automation technology for capturing and/or setting a process variable, the system comprising:

• a first two-wire line for transferring a loop current with a modulated two-wire signal;
• a field device of automation technology with a field device housing which has at least one housing opening, wherein the field device further comprises a field device electronics unit arranged within the field device housing, the field device electronics unit being designed to communicate data in the form of two-wire signals based upon a Highway Addressable Remote Transducer (HART) standard;
• and
• a field device adapter for wireless data transfer, the field device adapter including:
• an adapter housing having a first end and a second end, wherein the first end has a first connection element and a second connection element for electrically connecting to the field device electronics unit of the field device, and the second end has a third connection element and a fourth connection element for electrically connecting a two-wire line;
• and
• an adapter electronics unit arranged in the adapter housing, the adapter electronics unit including:
• a first electrical connection line connecting the first connection element to the third connection element;
• a second electrical connection line connecting the second connection element to the fourth connection element;
• a first supply circuit installed in the first electrical connection line for providing a first supply voltage from a loop current flowing in the first electrical connection line;
• a second supply circuit installed in the second electrical connection line for providing a second supply voltage from the loop current flowing in the second electrical connection line;
• a HART modem based upon the HART standard, wherein the HART modem is connected to the second electrical connection line via a tapping point arranged in the second electrical connection line and wherein the HART modem is configured to:
• tap a first two-wire signal modulated on the loop current and convert the first two-wire signal into a first universal asynchronous receiver transmitter (UART) signal;
• convert a supplied second UART signal into a second two-wire signal;
• and, via the tapping point, modulate the converted second two-wire signal onto the loop current;
• and
• a wireless module with an antenna for transmitting and receiving, wherein the wireless module is configured to:
• transmit as a first wireless signal the converted first UART signal supplied by the HART modem;
• receive a second wireless signal that is to be converted into the second two-wire signal by the HART modem;
• and supply the received second wireless signal as the second UART signal to the HART modem,
• wherein, in the adapter electronics unit, the first supply circuit is configured to supply the HART modem with the first supply voltage, the second supply circuit is configured to supply the wireless module with the second supply voltage, and the first supply circuit and the second supply circuit are configured to operate independently of each other.